My sister marched ahead, iPhone in hand, as Citymapper’s beeps led us through the urban sprawl of Barcelona’s Barri Gòtic (Gothic Quarter). Above, light filtered through a tapestry of clouds, capturing the minutiae of a quiet corner in the bustling capital. I walked a bit faster, careful not to trip over the cobblestones that had been worn down by centuries of use. It was that rare time of year when our family was all in one place, and we were determined to make the most of our annual vacation.

Where rickety wooden wheelbarrows onced hauled local produce now stepped the sandaled feet of world travelers, flocking to this jewel of the Iberian Peninsula. Winding through the narrow streetways, I observed children darting around in superhero T-shirts, shouting at each other in rapid-fire Catalan — apparently Iron Man had stolen Batman’s football. I saw a well-heeled group of women seated under sun hats at a hole-in-the-wall café, and watched tourists covered in sunblock eye the many side streets curiously as they adjusted to the urban terrain.

I breathed in the hot, dry air — a welcome contrast to the chill I had grown accustomed to in the U.K., or even the warm, humid atmosphere of my home in Bangkok. I reveled in the opportunity to be submerged in yet another new city. The smell of sizzling local cuisine began to make itself known, like a battle cry through the otherwise peaceful streets. It informed locals that the onslaught of queues was about to begin, and signaled to the waddling swarms of tourists that in this city of gold and stone, food reigned king.

I walked briskly as my sister led the way with my parents closely in tow — they did not want to abandon our imminent dinner reservation. When we turned the corner, I found myself at the mouth of a silent alleyway. With only a few residences and one or two drowsy shops lining the street, it felt like a road that had been forgotten in lieu of a more vibrantly colored pathway. I could make out the confident figure of my sister at its end and knew that the restaurant must be just around the corner.

As I rushed to catch up, a flash of gray darted behind me. Out of the corner of my eye, I spotted an old woman no taller than my chest. She looked like a silver relic subdued against the dusty, sun-kissed walls. Instinctively, I raised my camera. Gray curls fell upon her soft face and upturned nose. Her eyes, the shade of faded moonlight, hinted at someone who had been considered a great beauty in her youth. Her simple-gray dress suit fell upon hunched shoulders and fumbling knees.

She called out through an opening in the graffitied doorway that I had almost missed in my haste. Stretching out her hand, as if to reach into the darkness and grab it by its shrouded cloak, the woman passed by like a ghost. She ducked through the spray-painted doors and closed them behind her. In an instant, she was gone, leaving me to fumble forward with my camera around my neck and only one picture engrained on my memory card.

It was a fleeting moment, but the woman represented a glimpse of the history that wandered the city’s modern walkways.

Like a tourist, she existed alongside the weather-worn walls and rusted doors interspersed among the thriving chain of shops and LED-lit restaurant fronts, the metamorphosis of Romanesque facades and wrought-iron gates to spray-painted urban designs, and the generation of locals whose existence contributed the backbone of traditional Catalan culture. She was caught in, and yet blissfully unaffected by, the quiet revolution of youth that blossomed like a fiery rose in the desert of its rich past.

I hurried to catch up with my family, but stole one last glance at the alleyway, wondering when I would venture back into that vanishing world.